MP Select Mini Universal Bearing for stock spool holder

thingiverse

The Mini's stock spool holder is hard edged and jerks the filament when it's rolling. This creates excess vibration and resistance on the extruder gear, as well as being kind of noisy. This little 30-minute print fixes it in the simplest way possible. Just print the bearings upright with support touching the bed in the filament of your choice. drop them on the stock spool holder, and slide them under each end of your spools center hub. Taa-Daaah! A smoothly rolling filament feeding machine! These work with most standard sized .5kilo-1kilo spools. Haven't tested them on smaller spools, but they should work fine as long as the spool hub diameter is over 50mm (Don't be afraid to sand a little if you print at a larger layer height and the spool doesn't roll smooth. You might need to knock down the layer lines to get it really rolling.) Update: I taped off the bearings and coated the inside where it touches the spool arm with a coat of flexible rubber sealer. Bearings stay in place much better.